Panama, Mexico, the Pacific – to be honest, I never thought that I’d ever get to these places (at least not as a scientist). But, after many years, I left the Black Sea (by the way, I miss this moody sea with its sudden change of winds or spring storms) and here I am on the Pacific, studying its hydrochemistry.

Of course, my biologist colleagues could say “How boring!” and maybe they are right given their research fields can be considered as being more attractive since they observe and study life (!) of the abyssal seabed (=benthos). But for a better understanding of how all these organisms live, it is important to know their habitat’s conditions in terms of physical and chemical features. Anyway, here in the Pacific, the benthic organisms are privileged, as the living conditions are much better than in the Black Sea. Just look at the oxygen: here, in the bottom layers it reaches more than 3 mg/l, whereas in the Black Sea there is no oxygen from about 180 to 200 meters depth down to the bottom. So, lucky guys (except those, of course, collected during our sampling campaign)!

But coming back to the water column - the reason why I am here onboard SONNE. However, before I start to present you some of my findings, I’d like to thank Sarah, Inken and Matthias for their help in running the CTD. Once I learned to handle it and to process the CTD data, I went to the next step – data analysis, probably the more interesting step. I say that because the CTD profiles reveal some very fascinating features, especially in the mesopelagic zone, where we find layers featuring extreme values with regard to chemical and physical parameters. For example, a well contoured oxygen minimum zone (concentrations less than 0.1 ml/l in its core) can be seen between 120 and 1200 meters depth. Its thickness, though, shows quite a large spatial variability. In the upper layer, around the upper limit of the thermocline (which marks a zone of abrupt temperature change, in this case from warm tropical waters to cold deep water), the chlorophyll maximum layer can be seen, generally coinciding with a turbidity maximum. In terms of nutrients, there is a phosphate and nitrate maximum zone at about 900 to 1200 m depth (at the lower limit of oxygen minimum zone), while silicates show their maxima much deeper, that is in the bathypelagic zone, at depths between 2500 and 3500 meters. However, this is just a snap shot of my results and more details about the CTD and nutrients vertical profiles will be provided in the cruise report.

In another train of thoughts, most of the Romanians (me too) celebrated Easter yesterday (that is a week after everyone else), so I’d like to say, in Romanian, according to ancestral custom “Hristos a inviat!” (Christ is risen!).